Disclosed is a microwave phase shifter including switches each of which utilizes resonance between an off-capacitance of an FET and an inductor connected in parallel with the off-capacitance of the FET, an LPF, and an HPF, a series circuit of an inductor and an MIM capacitor is arranged in parallel with the FET in each portion of the resonance. In a layout of the LC series-connected circuit, though the inductor is of a non-close-packed structure, a metal member or a dielectric material having a relative dielectric constant higher than that of a dielectric substrate is arranged in a free space in a central portion of the inductor.